Rotary wing aircraft



Dec. 18, '1951 THQMPSQN 2,579,055

ROTARY WING AIRCRAFT I Filed Sept. 18, 1946 INVENTOR.

Patented Dec. 18, 1951 UNITED STATES PATENT OFFICE ROTARY WIN G AIRCRAFT Arthur M. Thompson, Chicago, Ill. Application September 18, 1946, Serial No. 697,743

2 Claims.

This invention relates to aircraft and more specifically involves certain new features directly incorporated in a helicopter. One of the main objects of the present invention is to provide a helicopter type of aircraft utilizing dual rotors which are positioned to operate in a common plane disposed in line with the propulsion unit for driving the aircraft. In this manner the backwash from the propeller or other propulsion unit is properly redirected to strike the blades of the rotors, and will actuate the blades or start the same rotating or cause the continued rotation thereof as the case may be. Heretofore it has been the practice to utilize power means for beginning the rotation of the blades prior to takeoff and also in flight. Although that is possible with a craft of the present construction, fundamentally the ship of the present design includes two freely rotating rotors laterally disposed to either side of the fuselage and in a plane substantially coincident with the median line of the entire ship which normally includes the axis of the propeller or propulsion means for driving the ship.

A further object of the present invention is to provide rotors of smaller overall diameters and of multi-blade construction to obtain the necessary lift, such blades also including inertia rings which function to obtain a flywheel effect transmitted to the blades of the rotor, such rings also acting to stiffen and stabilize the multi-blade rotors.

It is a further object of the present invention to provide struts that extend laterally to support the bearings and the rotors, such struts being streamlined in the air foil fashion to reduce resistance, and such struts and the blades of the rotors are so arranged that the blades as they recede from the line of flight pass directly below and adjacent to the supporting struts. In this manner the rush of air passing the craft or the backwash of the propeller or other propulsion unit is concentrated between the supporting struts and the individual blades of the rotor as the latter pass beneath such struts, whereby the reaction of such passing air or backwash air drives the rotors proper.

For the same purpose, the fuselage may be designed to also partially pocket airflow from passing air or from the propulsion unit to furtherconcentrate the same in the direction of the struts and in the direction of the receding blades of the rotors.

A further object of the present invention is to provide the rotors with channel members disvide air pockets for further trapping air passing the ship or being directed rearwardly thereof by the propulsion unit.

Although the craft has been described as including free-wheeling rotors, it is also possible and has been indicated that power take-off means may be provided for driving the rotors under certain conditions of operation. This mechanical means however does not have to be operated except possibly to perform certain maneuvers and is merely indicated as a modified arrangement that is selectively available if necessary.

A further object of the present invention is to provide a rotor and strut arrangement of the kind above referred to wherein a propulsion power unit may be utilized in aiding or driving the blades of the rotor. This may be accomplished by a suitable by-pass of the discharged gases as they flow through the discharge reaction tubes, and carrying a percentage of such gases to a relative long conduit that may be cooled through air flow and eventually terminating in a nozzle which will direct the by-passed gases against the blades of the rotor.

Further objects and advantages of the present invention shall hereinafter appear in the following detailed description having reference to the accompanying drawings forming a part; of this specification.

In the drawings:

Figure 1 is a side elevational view of a helicopter incorporating the principles set forth by the present invention;

Figure 2 is a plan view of the craft shown in Figure 1 further illustrating certain details of construction thereof;

Figure 3 is a detailed cross sectional view of one of the struts or stub wings with one of the blades of the rotor in position directly adjacent thereto;

Figure 4 is a fragmentary View of a modified construction of ship which incorporates a power take-off selectively operated by the pilot and through which the rotors may be mechanically driven if desired; and

Figure 5 isa fragmentary plan view, illustrated in reverse position from the plan view in Figure 2, showing a modified construction wherein the gases of a jet propelled craft are directed against the blades of the rotors of the craft.

Referring to the drawings, Figures 1 and 2 typify a diagrammatic picture of the general arrangement of the elements and design features posed on the receding face of the blades to pro- 66 of a; craft which embody the principles of the present invention. The craft is of a conventional type of helicopter having a fuselage l with a cabin 2 at the head end thereof, and a tall assembly 3 at the trailing end having conventional elevators 4 and the rudder 5. A suitable rotary engine 6 is conveniently incorporated in the forward end of the cabin 2 and provides the power.

for driving the multi-bladed propeller I which drives the craft.

Suitable tricycle landing gear in the form of a forward spring wheel 8 and rear landing wheel 9 is preferably used in this construction so as to provide a relatively even starting position for the craft which will place the rotors-of the helitively wide width at 19 and 20 adjacent the sides of the fuselage 2. The individual blades of the rotors pass directly beneath the struts l and II, and this particular relationship is maintained through a greater arc of each ofthe blades by reason of the wide portions 19 and 20 of each of the struts I0 and II. Referring more particularly'toFigures 2 and 3, it should be noted that each of the blades is 7 provided with elongated channels 2| and 22 se-- cured to the top of the receding sides of each of the blades to form air pockets which will function to trap the air from the backwash of the propeller or from the passing air of the craft as the latter moves through the air. in Figure 3 arrows 23 indicate generally a portion of this backwash air which is partially trapped in the triangular space 24 beneath the strut IE) and the receding side of the blade l6,v and As shown obviously entering the channels 2| and 22 which are preferably closed at their ends to further entrap such air thereby building up pressure for purposes of driving the blades and the entire rotors. The rotation of the rotors isindicated by the arrows in Figure 2 revolving in a direction which is most feasible in carrying out this particular principle of operation of the helicopter.

The use of dual rotors is to obtain balance in this particular type of an aircraft. Heretofore it has been'the practice to provide these ships with a single rotor disposed considerably above the top of the cabin or fuselage, and the difficulty has always been to maintain the tail assembly in the line of flight due to the reactionary forces created by the rotation of this rotor upon a freely-- rotating shaft having suitable bearing structure suspending the craft per se or through the use of a super-structure created for its support.

The backwash of the propeller 1 is generally indicated in Figure 2 through the dotted lines 25 and 26 which backwash encompasses or impinges against the greater portion of the blade ends while such backwash air by-passes the supporting struts l0 and II of the rotors l4 and IS. The fuselage 2 has a cabin so designed as to provide external and rearwardly converging lateral recesses 21 and 28 disposed in the general plane of rotation of the blades so as to further direct and concentrate some of the backwash air into the arc of operation of the receding blades of the rotors L4 and IS, the ends of such rotors passing through said fuselage recesses 21 and 28 during operative rotation. This may be accomplished in various other ways but primarily the principle is to concentrate and channel a portion of the backwash air of the propulsion unit and the by-flow of the air stream through which the craft flies to use such concentrated and guided air for the purpose of driving the rotors at a greater speed than the speeds heretofore obtained through the normal forward operation of the ship. Furthermore such concentration and guidance of the backwash air furnishes the means for beginning the rotation of the blades of the rotor prior to a takeoff with a helicopter of this construction. And whether the craft is of operation of the craft.

In Figure 4 the engine Sis provided with a rear power take-oil driving suitable dual chain drives 30 and 3| having a common clutch 32 of any conventional construction which may be operated by the hand lever 33 to drive the rotors. Each of the chain drives 30 and 3| are adapted through suitable power transmission means such as the shafts 34 and 35 and through the gear sets 36 and 31 to drive the main shaft 38 of the rotor [5; the same form of power transmission means also simultaneously driving the rotor I4 during the operative engagement of the clutch 32. When clutch 32 is inactive, both of the rotors will be free running just as in the preferred construction of craft illustrated in Figures 1 and 2.

The 'modified arrangement illustrated in Figure 5 involves the use of a conventional type of jet propulsion power unit 49 which exhausts through suitable vents All and 42 propelling the craft at high speeds through the air. With this class of a ship as a helicopter it is possible to use by-pass ducts 43 and 44, the latter having an intake opening such as 45 topartially bleed off some of the main gas flow through the propulsion unit. These ducts 43 and are positioned externally of the fuselage to cool the gases passing therethrough and each of the ducts terminates in a relatively large but fiat nozzle 46 which is adapted to'discharge the bled off gases from a position substantially in the plane tion with the present principles of operation embodied in the design of aircraft illustrated are all directed to the idea of providing a means for aiding or wholly furnishing the power for. rotating the rotors of a helicopter or the like. Furthermore, it should be noted that the Figure 2 construction illustrates a craft wherein weight and overall dimensions have been held to a minimum through the use of dual rotors of relatively small overall diameters which are multibladed and entirely or partially driven by means of the backwash fluid which is discharged from the propulsion units and/or by the flow of air or wind through the action of the forward movin craft.

The stub wings in the form of the struts I0 and H coact directly with the revolving blades which are equipped with the channel air pockets all functioning to produce the driving efiect which will spin the propellers in the manner hereinbefore described. The struts l0 and H may be suificiently reinforced to provide a sole means for supporting the rotors, although the bearings 12 and I3 may be further stabilized by suitable diagonal struts 41 and 48, indicated in Figure 1, which are similar to stabilizing and strengthening struts used for win structures in the conventional type of wing plane.

Other arrangements are also possible without departing from the general scheme and design of the aircraft disclosed, and it is obvious that the rotors need not necessarily be disposed to operate below the supporting wing struts but can also be positioned between pairs of wing struts which will coact to further entrap discharged or slip stream air to direct the same against the rotatin and receding wing tips of the blades of the rotors l4 and I5.

Other changes and modifications in the present construction are contemplated and the invention is not necessarily intended to be limited to the exact description and disclosure presented. All such deviations and changes shall be governed by the breadth and scope of the language of the appended claims which are directed to the salient features of the present invention.

What I claim is:

1. In an aircraft, the combination of a power unit having air propulsion means to drive said craft, and rotatable wings comprising rotary blades connected with said craft to support the same in flight, said blades being disposed to re ceive a portion of the backwash of said air propulsion means, and said craft having means for said blades to direct a part of said backwash portion along a predetermined path to cause the latter to react against and to rotate said blades of said rotatable wings comprising recesses in the body of said craft disposed in the general plane of rotation of said blades, said blades being arranged to permit the end portions thereof to pass through said craft recesses.

2. In an aircraft, a fuselage, laterally positioned supporting units to sustain the aircraft while in flight, each of said supporting units including rotatable means disposed to receive a current of air by reason of the forward motion of said craft to thereby cause rotation of said rotatable means, said fuselage havin side recesses forming air channels disposed in the general plane of the supporting units, and said units being arranged to have portions thereof pass through said fuselage channels and into the path of air currents concentrated in said channels.

ARTHUR M. THOMPSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

